The present invention relates to a flashing device for cameras, and more particularly, to controlling a charging of a condenser for supplying electricity to a flash after the flash emits flash light.
A flashing device can emit light at a specified voltage (hereinafter referred to as a first voltage), however, it is desirable to apply a voltage (hereinafter referred to as the second voltage) which is higher than the first voltage to the flashing device, in order to obtain the maximum luminous energy of the flashing device.
Conventionally, charging of a condenser for supplying voltage to the flashing device is performed through a voltage increasing circuit which is connected with a power source. However, when the recharging of the condenser to the second voltage (hereinafter referred to as a full charge) and light emission of the flash are successively repeated, elements such as transistors or a transformer in the voltage increasing circuit are undesirably heated and the voltage increasing circuit may be burnt or damaged.
Therefore, in order to prevent such problems, a device is suggested in which recharging is prohibited for a predetermined period of time after charging has been finished or flash light has been emitted.
In such a device, however, in order to allow the flash light emission and full charge to be repeatedly performed, a recharge prohibited time should be specified for a sufficiently long period of time so that the voltage increasing circuit is not undesirably heated.
If the recharge prohibited period is specified for a long time, however, there may arises a problem that the flash light emission can not be used immediately after the light emission, and promptness of the flashing device become lowered.